Repair alloy compositions

ABSTRACT

A Ni-base alloy composition comprises of Zr, B, and Si. Zr and B are coupled to each other to form ZrB 2 , the B and Zr suppress melting points of the Ni-base alloy composition. Further, a Ni-base alloy composition also comprises Cr, Ti, and Ni, where the Ti and Cr suppress melting points.

This application is a division of application Ser. No. 09/2927,138,filed Sep. 2, 1997, now U.S. Pat. No. 6,027,584 which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to repair alloy compositions. The repair alloycompositions provide a low melting point composition, and are desirablefor use in braze repair applications, especially for the repair ofengine and gas turbine components.

BACKGROUND OF THE INVENTION

Cracks, damaged areas and other similar defects in jet engine and gasturbine components, such as but not limited to turbine buckets, bladesand vanes, are of course extremely undesirable and dangerous if largerthan permitted by design practice and standards. The cracks, damagedareas and other similar defects are formed during service, and are due,in part, to effects of one or more of mechanical fatigue, thermalfatigue, creep rupture, and foreign object damage. Additionally,significant metal loss can occur by oxidation or corrosion in anengine's environment.

The cracks, damaged areas and other similar defects can be localized inan area of an engine component. The remainder of the area of an enginecomponent may be subjected to less severe stress and thermalenvironments, however these would not jeopardize performance of theengine component for many hours of continued service. In this situation,the repair of the engine component may have a significant economicsavings and value. The repair of the engine component need notnecessarily be to original performance levels, but need only be to apredetermined acceptable level of those original performance levels.

Currently, in order to repair engine components, damaged areas of theengine components are treated to clean any oxide from both externalairfoil surfaces and internal faces. Then any cracks, damaged areas, andother such defects are filled in with powder mixes, which are at leastpartially melted in a repair braze thermal cycle. The powder mixesinclude at least one low-melting powder composition, where the powdermixes will melt and flow, for example by capillary action. Thus, meltedflowing powder mixes will fill deep cracks, carrying somehigher-melting, still-solid, powders along with the flowing melt.

During the repair cycle, at least a partial dissolution of thehigher-melting powders and substrate surfaces occurs. The partiallydissolutionized higher-melting powders and substrate surfaces will flowinto the lower-melting liquid. This flow will continue until the liquidcomposition is altered, thus a melting range of the diluted meltedliquid composition is increased, and freezing of the liquid compositionoccurs.

The engine components often are formed from a composition comprising aNi-base alloy composition. Accordingly, to achieve a satisfactory flowin a low-melting alloy, various amounts of melting point depressants,such as Si and B, are commonly used in a Ni-base braze repair alloycomposition. These levels of melting point depressants can reach levelsup to about 6 atomic percent (a/o) Si and greater than about 12 a/o B.These levels of melting point depressants, such as Si and B, insurewetting of the solid surfaces of the engine components, andsignificantly reduce a melting range of the Ni-base braze repair alloycomposition, which contains the Si and B as melting point depressants.

However, these melting point depressant levels, such as Si and B, makerepeated repair procedures risky, because large portions of multiplyrepaired airfoils are often subject to melting in hot streak transients.The hot streak transients often occur in engine components during use.These levels of melting point depressants, such as Si and B, can alsolead to a decreased rupture life, since rupture is effected by theproximity of a service temperature to an incipient melting range, forthe compositions of the alloys in the engine component and the repairalloy composition.

Further, both B and Si constituents in a Ni-base braze repair alloycomposition can lead to large fractions of the repaired engine componentregions being converted to undesirable and often detrimental brittleintermetallics and intermediate phases. The brittle intermetallics andintermediate phases also comprise undesirable silicides and borides,which also are detrimental to engine components, especially whenrepaired.

SUMMARY OF THE INVENTION

Accordingly, it is desirable to provide a Ni-base braze repair alloycompositions that overcome the above noted, and other deficiencies.

Therefore, it is desirable to provide a Ni-base alloy composition, forbraze repair comprising: Zr, B and a balance Ni, where Zr and B arecoupled to each other to form ZrB₂. B and Zr suppress melting points ofthe Ni-base braze repair alloy composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a portion of a NiZrB phase diagramat the Ni-rich region of the NiZrB system; and

FIG. 2 is a schematic illustration of a NiCrTi phase diagram at a NiCrTiliquidus projection, at the Cr-lean region.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To adequately repair engine components, it is desirable to provide arepair alloy composition that approximates the strength of the alloyused to form the engine component itself. This, of course, will providea strength-wise alloy having an approximately equal strength gradientfrom the repair portion to the original engine component portion.Whereas, a Ni-base alloy is common for engine component constructionsfor its well-known beneficial characteristics, it is desirable toprovide a Ni-base braze repair alloy composition. The Ni-base brazerepair alloy composition will produce, and result in, a substance thatis as strong a repaired region as possible.

Ni-base braze repair alloy composition will produce and result in asubstance that is almost as strong as the substrate being repaired.Therefore, Ni-base braze repair alloy composition for the repairedregions should contain superalloy strengtheners. The superalloystrengtheners in the Ni-base braze repair alloy composition comprisesuperalloy strengtheners, such as, but not limited to at least one ofAl, W, Mo, Re, Ta and Nb.

Table I lists compositions of several single crystal (SC) anddirectionally solidified (DS) superalloy compositions (A, B and C), inatomic percent. These alloy have a Ni-base braze repair alloycomposition and comprise at least the listed constituents, with thebalance being Ni. Table I also lists alloy D, which contains Zr and B,which is Ni-base braze repair alloy composition. Further, Table 1 alsolists composition A1, as one Ni-base braze repair alloy composition, asembodied by the invention.

Ideally, a Ni-base braze repair alloy composition, as embodied by theinvention, will approach a repair alloy composition approximating a“repair alloy goal” composition. A “repair alloy goal” composition, suchas composition A1 is listed in Table I. Since the “repair alloy goal”composition provides a Ni-base braze repair alloy composition that isalmost as strong as the substrate being repaired, a Ni-base braze repairalloy composition that is close to the “repair alloy goal” compositionis desirable.

Further, a Ni-base braze repair alloy composition that approximates the“repair alloy goal” composition, when provided in a single powdercomposition, avoids undesirable inhomogeneities, which are inherent inmixtures of two or more powders. Also, a Ni-base braze repair alloycomposition that approximates the “repair alloy goal” composition wouldbe useful in a repair of very wide cracks, where high B and Siconcentrations lead to undesirable ductility and toughnesscharacteristics in the repair area of the engine component.

Further beneficial results in a Ni-base braze repair alloy composition,as embodied by the invention, are achieved by providing a high-meltingportion of a mix heavily concentrated with strengthening elements, suchas but not limited to at least one of Al, W, Mo, Re, Ta and Nb. Also,other of the numerous beneficial results in a Ni-base braze repair alloycomposition, as embodied in the invention, are achieved by providinglower-melting temperature components with low concentrations of meltingpoint depressants, such as but not limited to Si and B.

TABLE I Repair a/o Alloy A Alloy B Alloy C Alloy Goal Alloy D Al 9.313.8 13.7 12/14 12 Cr 11.1 8.1 7.9 8/9 8 Co 7.5 7.6 12.3 8 8 Ta 1.6 2.32.1 2 — B 0.03 0.03 0.1 <8 6 Mo 0.9 0.9 0.9 0.7 — W 2.0 1.6 1.6 0.8 — Re— 1.0 0.9 0.5 — C 0.2 0.2 0.6 0.2 — Hf 0.07 0.06 0.5 — — Other 0.3 Nb0.01 Y — — 3.0 Zr 4.3 Ti

Ni-base braze repair alloy composition, as embodied in the invention,comprise constituents, such as but not limited to at least B and Zr, inorder to improve single-chemistry repair alloys compositions that avoidinherent disadvantages associated with mixed two-chemistry repair alloypowders. Further, strengthening elements, which comprise at least onestrengthening element selected from the group consisting of, but notlimited to at least one of Al, W, Mo, Re, Ta and Nb, are also added tothe Ni-base braze repair alloy composition, as embodied in theinvention.

The strengthening element or strengthening elements, as discussed above,are added to the Ni-base braze repair alloy composition to providestrengthening element additions similar to the alloys being repaired.Also, a Ni-base braze repair alloy composition, as embodied by theinvention, is also produced with a low melting range for braze repairapplications.

The Ni-base braze repair alloy composition, as embodied by theinvention, is suitable for a single-chemistry Ni-base braze repair alloycomposition. The single-chemistry Ni-base braze repair alloycomposition, as embodied by the invention, also avoids difficultiesinherent in mixed powders that are used for alloy repair. Additionally,these Ni-base braze repair alloy compositions also are useful as alow-melting constituent in Ni-base braze repair alloy compositions, ifpowder blends are still desired, or as is some instances required.

The Ni-base braze repair alloy compositions, as embodied in theinvention, are listed in Table II by atomic percent (a/o) and in TableIII by weight percent (w/o). Table II also lists estimates of firstmelting temperatures and full melting temperatures. The estimates offirst melting temperatures and full melting temperatures for the Ni-basebraze repair alloy compositions are derived from differential thermalanalyses of Ni-base braze repair alloy compositions. These estimates offirst melting temperatures and full melting temperatures areapproximations, however they provide an indication of trends in liquidusand solidus, as a function of temperature.

TABLE II Ni-BASE BRAZE REPAIR ALLOY COMPOSITIONS (a/o) Temperatures in °F. Alloy (a/o) Ni Ti Cr Co B Si Al Zr Ta Mo W Re other solidus liquidusdelta A1 63 8 8 6 12 3 na na na A2 60 5 10 6 1 15 3 1906 2274 368 A3 618 8 6.5 1.5 12 3 1912 2265 353 AA 60.5 1.5 8 8 6.5 1.5 12 2 1916 2243327 A5 60.5 8 8 6.5 1.5 12 2 1.5 1918 2269 351 A6 57.5 8 8 6.5 1.5 12 31.5 1.5 0.5 1905 2272 367 A7 57 8 8 6.5 1.5 12 3 1.5 1 1 0.5 na na na A855 2.5 8 8 6.5 1.5 10 3 1.5 1 1 0.5 1.5 Nb 1916 2260 344 A9 60 2.5 8 8 31.5 10 1.5 1.5 1 1 0.5 1.5 Nb 1997 2325 328  A10 57.2 2.5 8 8 5 1.5 102.3 1.5 1 1 0.5 1.5 Nb  A11 51.6 1.2 10.8 11.4 5.2 4 9.4 3.1 1.4 0.6 10.3 Hf  A12 50 1.2 10.6 11.2 7.6 3.9 9.2 3. 1.4 0.6 1 0.3 Hf

TABLE III Ni-BASE BRAZE REPAIR ALLOY COMPOSITIONS (w/o) Alloy (w/o) NiTi Cr Co B Si Al Zr Ta Mo W Re other A1 70.47 7.93 8.98 1.24 6.17 5.21A2 68.49 5.05 11.46 1.26 .55 7.87 5.32 A3 69.16 8.03 9.10 1.36 .82 6.313.56 A4 69.24 1.40 8.11 9.19 1.37 .82 6.31 3.56 A5 66.65 7.81 8.85 1.32.79 6.08 3.42 5.08 A6 61.54 7.58 8.59 1.28 .77 5.90 4.99 2.62 5.03 1.70A7 59.90 7.45 8.44 1.26 .75 5.80 4.90 4.85 1.72 3.29 1.64 A8 56.89 2.117.33 8.31 1.24 0.74 4.75 4.82 4.78 1.69 3.24 1.64 2.46 Nb A9 60.79 2.077.18 8.14 0.56 0.73 4.66 2.36 4.68 1.66 3.17 1.60 2.40 Nb  A10 58.662.09 7.27 8.24 .94 .24 4.71 3.66 4.74 1.68 3.21 1.63 2.43 Nb  A11 54.01.0.0 10.0 12.0 1.0 2.0 4.5 5.0 5.0 1.0 3.0 1.5 Hf  A12 53.5 1.0 10.012.0 1.5 2.0 4.5 5.0 5.0 1.0 3.0 1.5 Hf

FIG. 1 is a schematic illustration of a portion of a NiZrB phase diagramfor a NiZrB system. The portion of the NiZrB phase diagram illustratesthe Ni-rich region of the NiZrB system. As illustrated, the NiZrB systemat the Ni-rich region exhibits deep eutectics of Ni, with Ni/B and Ni/Zrintermetallic phases. Therefore, due to the deep eutectics in the NiZrBsystem, Zr can be added to replace some of the B, which is provided formelting-point suppression.

Additionally, for many NiZrB compositions near the liquidus trough ofthe NiZrB system, thermodynamic stability of ZrB₂ promotes a Ni—ZrB₂equilibrium. Thus, for equivalent total B contents, Ni—ZrB₂ equilibriumpromotes a beneficial and desirable reduction in a volume fraction ofBrittle boride phases in the NiZrB composition when used for a repairedregion in a Ni-base braze repair alloy composition, as embodied in theinvention. The reduction in volume fraction of Brittle boride phases inthe repaired regions is a result of Zr bonding with, or “tying up,” two(2) boron atoms. This Zr bonding with two boron (B) atoms is contrary tothe types of bonds with other elements in a Ni-base braze repair alloycomposition, where a boride in equilibrium with Ni is normally in a formof at least one of MB, M₃B₂ or M₃B, so that a substantially much largervolume fraction of boride are formed for a given boron content.

As discussed above in Ni-base braze repair alloy compositions, a meltingrange depression is accomplished by the addition of at least Zr and B toNi-base braze repair alloy composition. Further, strengthening elements,such as but not limited to at least one of Al, W, Mo, Re, Ta and Nb canalso be added to the Ni-base braze repair alloy compositions. Theresulting Ni-base braze repair alloy composition, as embodied in theinvention, provides a useful and desirable melting range for brazerepair applications using a Ni-base braze repair alloy composition.

Further, Ni-base braze repair alloy compositions, as embodied in theinvention, have small additions of a melting point depressant, such asSi. The total amount of Si is less than the known and conventionallyutilized amounts of Si presently used in braze repair alloys, forexample those used in powder mixes. Known braze repair alloy powdermixes generally contain too much of a melting point depressant, forexample Si to be useful as single-chemistry alloys for repair alloycompositions and applications.

In theory, a Ni-base braze repair alloy composition, for example the“repair alloy goal” as discussed above, possesses a congruent meltingmaterial, i.e., a material having a “delta”=0. Further, the Ni-basebraze repair alloy composition will possess an incipient melttemperature at temperatures near about 1200° C. (2200° F.). Thesecharacteristics provide the Ni-base braze repair alloy composition withan increase in creep rupture life behavior, which shorter creep rupturelife may have resulted in known repair alloy compositions from incipientmelting effects in Ni-base repair alloy compositions.

Accordingly, with a Ni-base braze repair alloy composition used as asingle-chemistry Ni-base braze repair alloy composition, as embodied inthe invention, the single-chemistry Ni-base braze repair alloycomposition possesses a relatively high solidus temperature andrelatively small “delta.” In the Ni-base braze repair alloy composition,as embodied in the invention, additions of Zr increase the “delta” anddecrease the incipient melting temperature.

Solidus temperatures for most known Ni-base braze repair alloycompositions are relatively low. Therefore, there is a possibility thatwith use of a known Ni-base alloy composition, a liquid film will beformed at grain boundaries during use. The film may even exist overextended equilibration time periods, and may also be formed attemperatures below the expected use temperature. Therefore, in Ni-basebraze repair alloy compositions, as embodied in the invention, an atomicratio of B:Zr in a Ni-base braze repair alloy conventional compositionis generally around about 2:1, while a B:Zr ratio value in the Ni-basebraze repair alloy compositions is greater than about 5:1, as embodiedby the invention. These ratios produce a larger solidus temperature inthe Ni-base braze repair alloy compositions than is desirable.

In Ni-base braze repair alloy compositions, as embodied in theinvention, a temperature range over which a liquid film will be formedcan be advantageously reduced and the solidus temperature increased, byat least one of partial elimination and reduction of the amount of Zr.Thus, in a Ni-base repair alloy composition, as embodied in theinvention, the addition of at least one of Cr and Ti, to achieve atleast one of partial elimination and reduction the amount of Zr, thusproducing a decrease in liquidus temperatures, which is beneficial.

Selection of constituents of the Ni-base braze repair alloy compositionsshould provide alloys comprising at least Zr, B, Si, Cr, and Ti. Theconstituents of the Ni-base braze repair alloy compositions shouldcomprise about 1.5Zr, about 7.5B, about 1.5Si, with Cr levels increasedto a range of about 10 to about 14a/o, and Ti of about 5a/o. Thisselection of constituents for the Ni-base braze repair alloycompositions, as embodied in the invention, reduces liquidustemperatures. Other constituents, such as but not limited tostrengtheners, may be added to the above the Ni-base braze repair alloycomposition.

As further embodied in the invention, Ni-base braze repair alloycompositions, may take the form of low-melting powders. Thus, theNi-base braze repair alloy compositions in the form of a low-meltingpowder comprise low concentrations of melting point depressants, such asB and Si, and also comprise strengtheners, such as but not limited to atleast one of Al, Mo, W, Re, Ta, and Nb and avoids the above discussedtwo-chemistry disadvantages. The concentrations of melting pointdepressants, such as B and Si, are usually relatively low. Thestrengtheners, such as but not limited to, at least one of Al, Mo, W,Re, Ta, and Nb provide the Ni-base repair alloy composition with adesirable strengthening content when used for engine component repairedapplications.

The Ni-base braze repair alloy composition, as embodied by theinvention, comprises at least one of Ti and Cr, to depress meltingpoints of the Ni-base braze repair alloy composition. As embodied in theinvention, by mixing low temperature melting powders with hightemperature melting powders in a Ni-base braze repair alloy composition,for example a Ni-base braze repair alloy composition comprisingrelatively low amounts of Cr and Ti, the Ni-base braze repair alloycomposition in a repaired region of an engine component will approximatea substrate composition, at least in strength.

Further, a relatively low B and Si content in a Ni-base braze repairalloy composition also allows multiple repairs or applications to beconducted on the engine component. The multiple repairs or applicationsare due to the advantageous wetting and capillary flow characteristicsof the Ni-base braze repair alloy composition over the repair alloy.

FIG. 2 is a schematic illustration of a NiCrTi phase diagram at a NiCrTiliquidus projection, at the Cr-lean region in a further Ni-base brazerepair alloy composition, as embodied in the invention. The Cr-leanregion has relatively low melting temperatures because of lowtemperature eutectics between Ti and Ni₂Ti, and also between NiTi andNi₃Ti. Therefore, for a predetermined range of Ni-base braze repairalloy compositions, even substantial Cr concentrations can lead to lowmelting points, due to the presence of a Ni—Cr eutectic.

Ni-base alloy compositions, as known in the art, rely on Cr and Ti toproduce low-melting brazes. Some desirable strengthening elements, suchas at least one of Al, Mo, W, Re or Ta, raise a Ni-base braze repairalloy composition's melting ranges. Thus, the addition of appreciablequantities of the strengthening elements, such as but not limited to atleast one of Al, Mo, W, Re or Ta, might substantially impact theeffectiveness of Ni-base braze repair alloy compositions.

Ni-base braze repair alloy compositions, as discussed above and embodiedin the invention, comprise strengthening elements, such as but notlimited to at least one of Al, Mo, W, Re or Ta. The Ni-base braze repairalloy composition also comprises small concentrations of melting pointdepressants, such as B and Si. The relatively small concentrations ofmelting point depressants, such as B and Si maintain desirably lowmelting temperature ranges, and provide also beneficial capillary flowand wettability characteristics.

Tables IV and V list further Ni-base braze repair alloy compositions, asembodied in the invention, in terms of atomic percentages and weightpercentages, respectively. Table IV also lists estimated temperatures offirst melting temperatures and full melting temperatures taken fromdifferential thermal analyses for the Ni-base braze repair alloycompositions. These estimated temperatures are approximate, but providea satisfactory indication of the trends in liquidus and solidus as afunction of temperature for the individual Ni-base braze repair alloycompositions, as embodied in the invention.

As an example, Ni-base braze repair alloy composition A21 as embodied inthe invention, but in no way limiting of the invention, a Ni-base brazerepair alloy composition comprising Ti, in about 8-13 atomic percent(a/o) in combination with Cr in about 18-27 a/o. These Ni-base brazerepair alloy compositions provide a desirable range of meltingtemperatures for the Ni-base braze repair alloy composition, as embodiedin the invention, for an application as a repair alloy composition foran engine component.

Ni-base braze repair alloy compositions, without Zr further providedesirable melting temperature ranges. It is also possible to increase Alcontent in a Ni-base braze repair alloy composition, for example toabout 10 alo, to produce low temperature melting Ni-base braze repairalloy compositions for mixing with higher temperature melting powders.

TABLE IV Ni-BASE BRAZE REPAIR ALLOY COMPOSITIONS (a/o) Temperatures in °F. Alloy (a/o) Ni Ti Cr Co B Si Al Nb Zr Ta Mo W Re solidus liquidusdelta A13 35 13 36.5 5 4 1.5 1.5 1.5 1.5 0.5 2125 2219  94 A14 31 1336.5 5 2 1 4 1.5 1 1.5 1.5 1.5 0.5 2081 2303 222 A15 34.5 13 33 5 2 1 41.5 1 1.5 1.5 1.5 0.5 2090 2293 203 A16 37.5 13 30 5 2 1 4 1.5 1 1.5 1.51.5 0.5 2068 2172 104 A17 40.5 15 25 5 2 1 4 1.5 1 1.5 1.5 1.5 0.5 20552221 166 A18 40.5 13 27 5 2 1 4 1.5 1 1.5 1.5 1.5 0.5 2074 2179 105 A1939.5 11 30 5 2 1 4 1.5 1 1.5 1.5 1.5 0.5 2029 2169 140 A20 42.5 11 27 52 1 4 1.5 1 1.5 1.5 1.5 0.5 2022 2181 159 A21 44 11 22 5 2.5 1.5 7.5 1.51.5 1.5 1.5 0.5 2082 2198 116 A22 43 10 24 5 2 1 7.5 1.5 1 1.5 1.5 1.50.5 2017 2194 177 A23 47  8 22 5 2 1 7.5 1.5 1 1.5 1.5 1.5 0.5 2020 2165145 A24 47 10 20 5 2 1 7.5 1.5 1 1.5 1.5 1.5 0.5 2017 2173 156 A25 49 1018 5 2 1 7.5 1.5 1 1.5 1.5 1.5 0.5 2019 2179 156 A26 48  8 22 5 2 1 7.51.5 1.5 1.5 1.5 0.5 2082 2208 126 A27 48 10 20 5 2 1 7.5 1.5 1.5 1.5 1.50.5 2071 2199 128 A28 50 10 18 5 2 1 7.5 1.5 1.5 1.5 1.5 0.5 2074 2218144 A29 52  8 18 5 2 1 7.5 1.5 1.5 1.5 1.5 0.5 2070 2236 166 A30 40 2820 10 1 1 na na na A31 37 28 20 8 1 1 1.5 1.5 1.5 0.5 na na na A32 32 2820 8 1 1 3 3 3 1 2027 2448 421

TABLE V Ni-BASE BRAZE REPAIR ALLOY COMPOSITIONS (w/o) Alloy (w/o) Ni TiCr Co B Si Al Zr Ta Mo W Re A13 34.82 10.55 32.16 4.99 1.83 2.36 Nb 4.602.44 4.67 1.58 A14 31.34 10.72 32.68 5.07 0.37 0.48 1.86 1.57 + 4.682.48 4.75 1.60 2.40 Nb A15 34.74 10.68 29.43 5.05 0.37 0.48 1.85 1.56 +4.65 2.47 4.73 1.60 2.39 Nb A16 37.63 10.64 26.66 5.04 0.37 0.48 1.841.56 + 4.64 2.38 4.71 1.59 2.38 Nb A17 40.55 12.25 22.17 5.03 0.37 0.481.84 1.56 + 4.63 2.45 4.70 1.59 2.38 Nb A18 40.50 10.61 23.91 5.02 0.370.48 1.84 1.55 + 4.62 2.45 4.70 1.58 2.37 Nb A19 39.49 8.97 26.56 5.020.37 0.48 1.84 1.55 + 4.62 2.45 4.70 1.58 2.37 Nb A20 42.34 8.94 23.825.00 0.37 0.48 1.83 1.55 + 4.61 2.44 4.68 1.58 2.36 Nb A21 44.97 9.1719.92 5.13 0.47 0.73 3.52 2.43 Nb 4.73 2.51 4.80 1.62 A22 43.43 8.2421.47 5.07 0.37 0.48 3.48 1.57 + 4.67 2.48 4.74 1.60 2.40 Nb A23 47.186.55 19.56 5.04 .37 .48 3.46 1.56 + 4.65 2.46 4.72 1.59 2.38 Nb A2447.25 8.20 17.81 5.05 .37 .48 3.47 1.56 + 4.65 2.46 4.72 1.59 2.39 NbA25 49.15 8.18 15.99 5.03 .37 .48 3.46 1.56 + 4.64 2.46 4.71 1.59 2.38Nb A26 48.46 6.59 19.67 5.07 .37 .48 3.48 2.40 Nb 4.67 2.47 4.74 1.60A27 48.53 8.25 17.91 5.07 .37 .48 3.48 2.40 Nb 4.67 2.48 4.75 1.61 A2850.43 8.23 16.08 5.06 .37 .48 3.48 2.39 Nb 4.66 2.47 4.75 1.60 A29 52.266.56 16.02 5.04 .37 .48 3.46 2.39 Nb 4.65 2.46 4.72 1.59 A30 43.83 25.0419.41 11.00 .20 .52 A31 37.16 22.93 17.78 8.06 .18 .48 4.64 2.46 4.721.59 A32 29.64 21.16 16.41 7.44 .17 .44 8.56 4.54 8.70 2.94

While the embodiments described herein are disclosed, it will beappreciated from the specification that various combinations ofelements, variations or improvements therein may be made by thoseskilled in the art that are within the scope of the invention.

What is claimed is:
 1. A Ni-base alloy composition comprising: Zr; B;and and balance Ni, wherein Zr and B are coupled to each other to formZrB₂, and B and Zr suppress melting points of the Ni-base alloycomposition.
 2. A composition according to claim 1, further comprisingat least one further melting point suppressant.
 3. A compositionaccording to claim 2, wherein the further melting point suppressantcomprises of at least Si.
 4. A composition according to claim 1, furthercomprising at least one strengthener.
 5. A composition according toclaim 4, the strengthener comprising at least one strengthener selectedfrom the group consisting of: Al, W, Mo, Re, Ta, and Nb.
 6. Thecomposition of claim 5, herein the strengthener comprising at least onestrengthener selected from the group consisting of: Al, W, Mo, Re, Ta,and Nb, where Al is in a range of about 4.0-15.0 atomic percent; W is ina range up to about 3.0 atomic percent, Mo is in a range up to about 3.0atomic percent, Re is in a range of about 0.2 to about 1.5 atomicpercent, Ta is in a range of up to about 3.0 atomic percents and Nb isin a range of about 0.2 to about 2.5 atomic percent.
 7. A compositionaccording to claim 1, wherein a ratio of B:Zr is in a range of about 2:1to about 5:1.
 8. A composition according to claim 7, wherein the ratioof B:Zr is about 2:1.
 9. A composition according to claim 7, wherein Zris in a range of about 1.0 to about 4.0 atomic percent and B is in arange of about 3.0 to about 8.0 atomic percent.
 10. A compositionaccording to claim 7, further comprising of at least one constituentselected from the group consisting of: Cr, Co, and Al.
 11. A compositionaccording to claim 1, further comprising: Cr, Co, and Al.
 12. Acomposition according to claim 10, wherein Cr is in a range of about 4.0to about 12.0 atomic percent; Co is in a range of about 4.0 to about12.0 atomic percent; and Al is in a range of about 5.0 to about 15.0atomic percent.
 13. A composition according to claim 1, furthercomprising Hf.
 14. A composition according to claim 1, furthercomprising Ti, wherein Ti is in a range up to about 3.0 atomic percent.15. The composition according to claim 3, wherein Si is present in therange of about 0.5 atomic percent to about 3.0 atomic percent.